I'm doing the following experience:
I have a pressure sensor and I'm doing some readings using a Raspberry Pi 4 and a Black Pill (STM32F411CEU6), using an I2C connection. The sensor has pull-up resistors to 3.3V.
My problem is when I connect both RPI and the BP. In that setup, the BP is not capable to find the pressure sensor because of some conflict with the RPI. But at the moment I disconnect the RPI, the BP is able to find the sensor.
I have tried to disable the I2C from the RPI but did not work. I know that the RPI as pull-up resistors connected to its I2C pins but I don't understand how they could be reason for the problem, when the sensor itself also as pull-up resistors.